Light emitting diode chip having wavelength converting layer and method of fabricating the same, and package having the light emitting diode chip and method of fabricating the same

ABSTRACT

An exemplary embodiment of the present invention discloses an LED chip including a substrate, a GaN-based compound semiconductor stacked structure arranged on the substrate, an electrode electrically connected to the semiconductor stacked structure, and a wavelength converting layer covering a portion of the semiconductor stacked structure. The electrode passes through the wavelength converting layer. The semiconductor stacked structure includes a first conductivity-type semiconductor layer, an active layer, and a second conductivity-type semiconductor layer.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority from and the benefit of Korean PatentApplication No. 10-2010-0046423, filed on May 18, 2010, Korean PatentApplication No. 10-2010-0090352, filed on Sep. 15, 2010, Korean PatentApplication No. 10-2010-0096682, filed on Oct. 5, 2010 and Korean PatentApplication No. 10-2010-0110149, filed on Nov. 8, 2010, which are herebyincorporated by reference for all purposes as if fully set forth herein.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a light emitting diode (LED) chip and amethod of fabricating the same, and a package having the LED chip and amethod of fabricating the same, and more particularly, to an LED chiphaving a wavelength converting layer and a method of fabricating thesame, and a package having the LED chip and a method of fabricating thesame.

2. Discussion of the Background

LEDs are currently used as backlight sources in various types of displaydevices including cellular phones and the like. LEDs may be light, thin,and small, and may have energy-saving and long-lifespan characteristics.Since light emitting devices having LEDs mounted therein, i.e., LEDpackages, may implement white light with a high color renderingproperty, LED packages may be used for general illumination whilesubstituting for white light sources such as fluorescent lamps.

Meanwhile, there are a variety of methods for implementing white lightusing LEDs, and a method may be used, in which white light isimplemented through the combination of an InGaN LED to emit blue lightof 430 nm to 470 nm and a phosphor to covert the blue light into lightof a longer wavelength. For example, white light may be implementedthrough the combination of a blue LED and a yellow phosphor to beexcited by the blue LED, the yellow phosphor to emit yellow light orthrough the combination of a blue LED, a green phosphor and a redphosphor.

A white light emitting device may be formed by applying a resincontaining a phosphor in a recess region of a package having an LEDmounted therein. However, as the resin is applied in the package, thephosphor may not be uniformly distributed in the resin, and it may bedifficult to form the resin having a uniform thickness.

Accordingly, a method of attaching a wavelength converting sheet onto anLED has been researched. For example, the wavelength converting sheetmay be formed by mixing a phosphor into glass or the like. Thewavelength converting sheet may be attached on a top surface of the LED,so that white light can be implemented at a chip level.

However, since the wavelength converting sheet is attached on the topsurface of the LED, it may be limited to implement white light in an LEDin which light is configured to be mostly emitted through the topsurface of the LED. Further, the wavelength conversion using thewavelength converting sheet may not be suitable in an LED in which aconsiderable amount of light is configured to be emitted through sidesurfaces of the LED, e.g., to side surfaces of a growth substrate.

Meanwhile, when a resin containing a phosphor is applied in a package, awire may be bonded to an LED, and the resin is then applied thereto.Hence, it may not matter even if an electrode of the LED is covered withthe resin containing the phosphor. However, when a wavelength convertinglayer is formed at the chip level, it may be necessary to bond the wireto the LED after the wavelength converting layer is formed.

SUMMARY OF THE INVENTION

Exemplary embodiments of the present invention provide a light emittingdiode (LED) chip and a method of fabricating the same capable ofperforming light conversion such as wavelength conversion at a chiplevel.

Exemplary embodiments of the present invention also provide an LED chipand a method of fabricating the same capable of performing wavelengthconversion with respect to light emitted through side surfaces of asubstrate.

Exemplary embodiments of the present invention also provide an LED chipand a method of fabricating the same capable of performing lightconversion such as wavelength conversion and performing wire bonding.

Exemplary embodiments of the present invention provide an LED chipcapable of preventing light converted in a wavelength converting layerfrom being incident into the LED chip.

Exemplary embodiments of the present invention provide an LED chipcapable of preventing a wavelength converting layer from being damagedby light.

Additional features of the invention will be set forth in thedescription which follows, and in part will be apparent from thedescription, or may be learned by practice of the invention.

An exemplary embodiment of the present invention discloses an LED chipincluding a substrate, a GaN-based compound semiconductor stackedstructure arranged on the substrate, an electrode electrically connectedto the semiconductor stacked structure, and a wavelength convertinglayer covering an upper portion of the semiconductor stacked structure.In the LED chip, the additional electrode passes through the wavelengthconverting layer. The semiconductor stacked structure including a firstconductivity-type semiconductor layer, an active layer and a secondconductivity-type semiconductor layer.

An exemplary embodiment of the present invention also discloses an LEDchip including a substrate, a plurality of semiconductor stackedstructures arranged on the substrate, a first electrode electricallyconnected to a first semiconductor stacked structure, a second electrodeelectrically connected to a second semiconductor stacked structure, anda wavelength converting layer covering a portion of each of theplurality of semiconductor stacked structures. In the LED chip, thefirst electrode and the second electrode pass through the wavelengthconverting layer. The plurality of semiconductor stacked structures eachincludes a first conductivity-type semiconductor layer, an active layer,and a second conductivity-type semiconductor layer.

An exemplary embodiment of the present invention also discloses an LEDpackage including a lead terminal, an LED chip as described above, and abonding wire connecting the lead terminal and the LED chip. In the LEDchip, the bonding wire connects the electrode and the lead terminal.

An exemplary embodiment of the present invention also discloses a methodof fabricating an LED chip, the method including arranging a pluralityof bare chips on a support substrate, wherein each of the bare chipsincludes a substrate, a GaN-based compound semiconductor stackedstructure positioned on the substrate, and an electrode electricallyconnected to the semiconductor stacked structure, forming a transparentcoating layer covering the plurality of bare chips and the electrodes onthe support substrate, removing a portion of the transparent coatinglayer to expose the electrodes, removing the support substrate, andseparating the plurality of bare chips into individual LED chips. Thesemiconductor stacked structure includes a first conductivity-typesemiconductor layer, an active layer, and a second conductivity-typesemiconductor layer.

An exemplary embodiment of the present invention also discloses an LEDpackage including a submount substrate, a bare chip mounted on thesubmount substrate, the bare chip including a first conductivity-typesemiconductor layer, an active layer, a second conductivity-typesemiconductor layer, a first electrode electrically connected to thefirst conductivity-type semiconductor layer, and a second electrodeelectrically connected to the second conductivity-type semiconductorlayer, the bare chip having at least one of the first electrode and thesecond electrode arranged on a top surface thereof, and a wavelengthconverting layer exposing the at least one of the first electrode andthe second electrode, the wavelength converting layer covering a topsurface and side surfaces of the bare chip, and covering at least aportion of a top surface of the submount substrate.

An exemplary embodiment of the present invention also discloses a methodof fabricating an LED package, the method including mounting a pluralityof bare chips on a substrate, each of the plurality of bare chipsincluding a first conductivity-type semiconductor layer, an activelayer, and a second conductivity-type semiconductor layer, forming afirst electrode electrically connected to the first conductivity-typesemiconductor layer and forming a second electrode electricallyconnected to the second conductivity-type semiconductor layer, andforming a wavelength converting layer exposing at least one of the firstelectrode and the second electrode, the wavelength converting layercovering a top surface and side surfaces of each of the bare chips, andcovering at least a portion of a top surface of the substrate.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory and areintended to provide further explanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this specification, illustrate embodiments of the invention, andtogether with the description serve to explain the principles of theinvention.

FIG. 1 is a sectional view illustrating a light emitting diode (LED)chip according to an exemplary embodiment of the present invention.

FIG. 2 is a sectional view illustrating an LED chip according to anexemplary embodiment of the present invention.

FIG. 3 is a sectional view illustrating an LED chip according to anexemplary embodiment of the present invention.

FIG. 4 is a sectional view illustrating an LED chip according to anexemplary embodiment of the present invention.

FIG. 5 is a sectional view illustrating an LED chip according to anexemplary embodiment of the present invention.

FIG. 6 is a sectional view illustrating an LED chip according to a anexemplary embodiment of the present invention.

FIG. 7 is a sectional view illustrating an LED chip according to anexemplary embodiment of the present invention.

FIG. 8 is a sectional view illustrating an LED chip according to anexemplary embodiment of the present invention.

FIG. 9 is a sectional view illustrating an LED chip according to anexemplary embodiment of the present invention.

FIG. 10 is a sectional view illustrating an LED chip according to anexemplary embodiment of the present invention.

FIG. 11 is a sectional view illustrating an LED chip according to anexemplary embodiment of the present invention.

FIG. 12 is a sectional view illustrating an LED chip according to anexemplary embodiment of the present invention.

FIG. 13 is a sectional view illustrating an LED chip according to anexemplary is embodiment of the present invention.

FIG. 14 is a sectional view illustrating an LED chip according to anexemplary embodiment of the present invention.

FIG. 15 is a sectional view illustrating an LED chip according to anexemplary embodiment of the present invention.

FIG. 16 is a sectional view illustrating an LED chip according to anexemplary embodiment of the present invention.

FIG. 17 is a sectional view illustrating an LED chip according to anexemplary embodiment of the present invention.

FIG. 18 is a sectional view illustrating an LED chip according to anexemplary embodiment of the present invention.

FIG. 19 is a sectional view illustrating an LED package having an LEDchip mounted therein according to an exemplary embodiment of the presentinvention.

FIG. 20 shows sectional views illustrating a method of fabricating anLED chip according to an exemplary embodiment of the present invention.

FIG. 21 is a top plan view illustrating an LED according to an exemplaryembodiment of the present invention.

FIG. 22 is a sectional view of the LED taken along line C-C′ of FIG. 21.

FIG. 23 is a view showing a submount substrate having a plurality ofLEDs formed thereon according to an exemplary embodiment of the presentinvention.

FIG. 24 is an enlarged view of a region indicated by a circle in FIG.23.

FIG. 25 is a flowchart illustrating a method of fabricating an LEDpackage according to an exemplary embodiment of the present invention.

FIG. 26 shows sectional views sequentially illustrating processes offabricating the LED package according to an exemplary embodiment of thepresent invention.

FIG. 27 is a sectional view illustrating the LED package having the LEDmounted therein according to an exemplary embodiment of the presentinvention.

FIG. 28 is a sectional view illustrating an LED according to anexemplary embodiment of the present invention.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

Hereinafter, exemplary embodiments of the present invention will bedescribed in detail with reference to the accompanying drawings. Thefollowing exemplary embodiments are provided only for illustrativepurposes so that those skilled in the art can fully understand thespirit of the present invention. Therefore, the present invention is notlimited to the following exemplary embodiments but may be implemented inother forms. In the drawings, the widths, lengths, thicknesses and thelike of elements may be exaggerated for convenience of illustration.Like reference numerals indicate like elements throughout thespecification and drawings.

It will be understood that when an element or layer is referred to asbeing “on” or “connected to” another element or layer, it can bedirectly on or directly connected to the other element or layer, orintervening elements or layers may be present. In contrast, when anelement is referred to as being “directly on” or “directly connected to”another element or layer, there are no intervening elements or layerspresent.

FIG. 1 is a sectional view illustrating a light emitting diode (LED)chip 101 according to an embodiment of the present invention.

The LED chip 101 includes a substrate 21; a GaN-based semiconductorstacked structure including a first conductive semiconductor layer 25,an active layer 27 and a second conductive semiconductor layer 29; afirst electrode 41; a second electrode 42; a first additional electrode43; a second additional electrode 44; and a transparent coating layer,e.g., a wavelength converting layer 50. A buffer layer 23 may beinterposed between the first conductive semiconductor layer 25 and thesubstrate 21.

The substrate 21 has a top surface on which the semiconductor stackedstructure is positioned, a bottom surface opposite to the top surface,and side surfaces to connect the top and bottom surfaces. The substrate21 is not particularly limited as long as it is a transparent substrate.The substrate may be a substrate, e.g., a sapphire substrate, a siliconcarbide substrate, a spinel substrate or a silicon substrate, on which anitride semiconductor layers can be grown. The substrate 21 may berelatively thicker than the semiconductor stacked structure, and aportion of light generated in the semiconductor stacked structure may beemitted through the side surfaces of the substrate 21.

The active layer 27 and the first and second conductive semiconductorlayers 25 and 29 may be made of a III-N-based compound semiconductor,e.g., an (Al, Ga, In)N semiconductor. Each of the first and secondconductive semiconductor layers 25 and 29 may have a single- ormulti-layered structure. For example, the first conductive semiconductorlayer 25 and/or the second conductive semiconductor layer 29 may includea contact layer and a clad layer, and may further include a superlatticelayer. In addition, the active layer 27 may have a single or multiplequantum well structure. For example, the first and second conductivesemiconductor layers 25 and 29 may be n-type and p-type semiconductorlayers, respectively, but the present invention is not limited thereto.That is, the first and second conductive semiconductor layers 25 and 29may be p-type and n-type semiconductor layers, respectively. The bufferlayer 23 relaxes lattice mismatch between the substrate 21 and the firstconductive semiconductor layer 25, thereby reducing the defect densityinduced in the semiconductor layers 27 and 29.

Meanwhile, the first electrode 41 is electrically connected to the firstconductive semiconductor layer 25 by coming in contact with an exposedsurface of the first conductive semiconductor layer 25. The secondelectrode 42 is positioned on top of the second conductive semiconductorlayer 29 and electrically connected to the second conductivesemiconductor layer 29. For example, the first and second electrodes 41and 42 may include Ti, Cu, Ni, Al, Au or Cr, and may be made of two ormore materials thereof. A transparent conductive layer (not shown) suchas Ni/Au, ITO, IZO or ZnO may be formed on the second conductivesemiconductor layer 29 in order to disperse the current, and the secondelectrode 42 may come in contact with the transparent conductive layer.

The first and second additional electrodes 43 and 44 are positioned onthe first and second electrodes 41 and 42, respectively. The first andsecond additional electrodes 43 and 44 are narrower than the first andsecond electrodes 41 and 42, respectively. That is, the widths of firstand second additional electrodes 43 and 44 are limited to the widths ofupper portions of the first and second electrodes 41 and 42,respectively. That is, the first and second additional electrodes 43 and44 may be as wide as, but not wider than, the first and secondelectrodes 41 and 42, respectively. The first and second additionalelectrodes 43 and 44 may have shapes that become narrower as they extendaway from the first and second electrodes 41 and 42, respectively.Through such shapes, the first and second additional electrodes 43 and44 may be stably attached to the respective first and second electrodes41 and 42, which may improve a subsequent process such as a wire bondingprocess. The ratio of height to bottom surface area in each of the firstand second additional electrodes 43 and 44 may be limited within apredetermined range so that the first and second additional electrodes43 and 44 can be stably maintained on the first and second electrodes 41and 42, respectively.

The wavelength converting layer 50 may be formed with a phosphorcontained in epoxy or silicon, or may be formed using only a phosphor.For example, the wavelength converting layer 50 may be formed bydisposing a phosphor in epoxy or silicon and then applying the epoxy orsilicon with the phosphor contained therein. In this case, a mold may beused so that the wavelength converting layer 50 with a uniform thicknessis formed on the side surfaces of the substrate 21. The wavelengthconverting layer 50 may be formed by disposing the mold so that thewhole top surface or a portion of the top surface of each of the firstand second additional electrodes 43 and 44 is exposed. Alternatively,the top surface of each of the first and second additional electrodes 43and 44 may be exposed by applying a resin containing a phosphor to covereach of the first and second additional electrodes 43 and 44 and thenmechanically polishing the resin. Accordingly, the wavelength convertinglayer 50 having a flat top surface is formed, and the first and secondadditional electrodes 43 and 44 are exposed to the outside of the LEDchip 101 by passing through the wavelength converting layer 50.Alternatively, the first and second additional electrodes 43 and 44 maynot pass completely through the wavelength converting layer 50, andcontact holes may be formed to allow electrical connection with thefirst and second additional electrodes 43 and 44. Another alternative isthat wires may connect to the first and second additional electrodes 43and 44, respectively, and the wavelength converting layer 50 may beformed around the wires, and the wires are exposed to the outside of theLED chip 101.

Furthermore, the wavelength converting layer 50 may have a refractiveindex ranging, e.g., from 1.4 to 2.0, and TiO₂, SiO₂ or Y₂O₃ may beincorporated into the wavelength converting layer 50 so as to controlthe refractive index. These materials may be in powder form, forexample.

Meanwhile, as shown in the figure, the top surface of the firstadditional electrode 43 may be positioned at the same height as the topsurface of the second additional electrode 44. Thus, when the firstconductive semiconductor layer 25 is exposed by removing a portion ofthe second conductive semiconductor layer 29 and the active layer 27,the first additional electrode 43 may be longer than the secondadditional electrode 44 as shown in this figure.

The wavelength converting layer 50 may cover the side surfaces of thesubstrate 21 and the upper portion of the semiconductor stackedstructure 30. Thus, it is possible to form the LED chip 101 capable ofperforming wavelength conversion not only with respect to light emittedthrough the top surface of the semiconductor stacked structure 30 butalso with respect to light emitted though the side surfaces of thesubstrate 21. That is, wavelength conversion may be performed withrespect to light emitted out of the top surface and the side surfaces ofthe LED chip 101.

FIG. 2 is a sectional view illustrating an LED chip 102 according to anexemplary embodiment of the present invention.

Referring to FIG. 2, the LED chip 102 according to this exemplaryembodiment is almost similar to the LED chip 101 of FIG. 1, but isdifferent in that the LED 102 further includes a spacer layer 33, alower distributed Bragg reflector (DBR) 45 and a metal layer 47. Atransparent conductive layer 31 is interposed between the spacer layer33 and the second conductive semiconductor layer 29 of the semiconductorstacked structure 30. The second electrode 42 may be connected to thetransparent conductive layer 31. In this exemplary embodiment, detaileddescriptions of components identical to those of the LED chip 101 of theaforementioned exemplary embodiment will be omitted to avoid redundancy.

The spacer layer 33 may cover the upper portion of the semiconductorstacked structure 30 and the transparent conductive layer 31. Thewavelength converting layer 50 is spaced apart from the semiconductorstacked structure 30 by the spacer layer 33. The spacer layer 33 may bemade of, for example, silicon nitride or silicon oxide. The spacer layer33 may be implemented as a DBR formed by alternately stacking insulatinglayers with different refractive indices, e.g., SiO₂/TiO₂ or SiO₂/Nb₂O₅.In this case, the optical thicknesses of the insulating layers with thedifferent refractive indices may be controlled, so that the spacer layer33 can transmit light generated in the active layer 27 and reflect lightincident from the outside or converted in the wavelength convertinglayer 50. The DBR has a reflection band in which the DBR reflects lightin a long-wavelength region of the visible light region and transmitsshort-wavelength visible light or ultraviolet light generated in theactive layer 27. Particularly, since the optical absorptance of theNb₂O₅ is relatively lower than that of the TiO₂, the DBR may be formedusing SiO₂/Nb₂O₅ so as to prevent light loss.

Meanwhile, the lower DBR 45 is positioned on the bottom of the substrate21. The lower DBR 45 is formed by alternately stacking insulating layerswith different refractive indices, and has a relatively highreflexibility, preferably a reflexibility of 90% or higher, not onlywith respect to light in a blue wavelength region, e.g., light generatedin the active layer 27 but also with respect to light in a yellowwavelength region or light in a green wavelength region and/or a redwavelength region. Further, the lower DBR 45 may entirely have areflexibility of 90% or higher throughout the wavelength region ranging,e.g., from 400 nm to 700 nm.

The lower DBR 45 having a relatively high reflexibility throughout awide wavelength region is formed by controlling the respective opticalthicknesses of the material layers repeatedly stacked therein. Forexample, the lower DBR 45 may be formed by alternately stacking a firstlayer of SiO₂ and a second layer TiO₂ or by alternately stacking a firstlayer of SiO₂ and a second layer of Nb₂O₅. Since the optical absorptanceof the Nb₂O₅ is relatively lower than that of the TiO₂, it may bealternately stacked so that there is a first layer of SiO₂ and a secondlayer of Nb₂O₅. As the stacking number of the first and second layersincreases, the reflexibility of the lower DBR 45 is more stable. Forexample, the total stacking number of the first and second layers in thelower DBR 45 may be 50 or more, i.e., 25 or more pairs of first andsecond layers may be stacked.

All the first or second layers alternately stacked in the lower DBR 45do not necessarily have the same thickness, but the thickness of each ofthe first and second layers may be selected in order to have arelatively high reflexibility not only with respect to the wavelength oflight generated in the active layer 27 but also with respect to anotherwavelength in the visible light region. Alternatively, the lower DBR 45may be formed by stacking a plurality of DBRs each having a highreflexibility with respect to a specific wavelength band.

The lower DBR 45 is employed, so that when light converted in thewavelength converting layer 50 is again incident toward the substrate21, the incident light can be again reflected to be emitted to theoutside, thereby improving light emission efficiency.

Meanwhile, the first and last layers in the lower DBR 45 may be made ofSiO₂. The SiO₂ is disposed as the first and last layers in the lower DBR45, so that the lower DBR 45 can be stably attached to the substrate 21.Further, the lower DBR 45 can be protected using a last layer formed ofSiO₂.

The metal layer 47 is positioned on the bottom of the lower DBR 45. Themetal layer 47 may be made of a reflective metal such as aluminum so asto reflect light transmitted through the lower DBR 45, or may be made ofanother metal. Moreover, the metal layer 47 may help heat generated inthe semiconductor stacked structure 30 to be dissipated to the outside,thereby enhancing the heat dissipation performance of the LED chip 102.

According to this exemplary embodiment, the spacer layer 33 is formedwith a DBR having a high reflexibility with respect to thelong-wavelength visible light, so that it is possible to prevent lightconverted in the wavelength converting layer 50 from being againincident into the semiconductor stacked structure 30. Further, the lowerDBR 45 is employed, so that when light from the outside is incidenttoward the substrate 21 or when light converted in the wavelengthconverting layer 50 is incident toward the substrate 21, the incidentlight can be reflected, thereby improving the light emission efficiency.

FIG. 3 is a sectional view illustrating an LED chip 103 according to anexemplary embodiment of the present invention.

Referring to FIG. 3, the LED chip 103 is similar to the LED chip 102described with reference to FIG. 2, also includes a stress relaxationlayer 35 and an upper DBR 37 interposed between the wavelengthconverting layer 50 and the semiconductor stacked structure, in additionto the spacer layer 33 or in place of the spacer layer 33. That is, thestress relaxation layer 35 may be positioned above the semiconductorstacked structure 30, e.g., on the spacer layer 33, and the upper DBR 37is positioned on the stress relaxation layer 35. The stress relaxationlayer 35 and the upper DBR 37 also serve as spacer layers.

The upper DBR 37 may be formed by alternately stacking insulating layerswith different refractive indices, e.g., SiO₂/TiO₂ or SiO₂/Nb₂O₅. Inthis case, the optical thicknesses of the insulating layers with thedifferent refractive indices are controlled, so that the upper DBR 37can transmit light generated in the active layer 27 and reflect lightincident from the outside or converted in the wavelength convertinglayer 50. The upper DBR 37 has a reflection band in which it reflectslight in a long-wavelength region of the visible light region andtransmits short-wavelength visible light or ultraviolet light generatedin the active layer 27. Particularly, since the optical absorptance ofthe Nb₂O₅ is relatively lower than that of the TiO₂, the DBR may beformed using the SiO₂/Nb₂O₅ so as to prevent light loss.

Meanwhile, the stress relaxation layer 35 may be made of a spin on glass(SOG) or a porous silicon oxide film. The stress relaxation layer 35allows the stress of the upper DBR 37 to be reduced to prevent thedetachment of the upper DBR 37 from the LED chip 101.

When the upper DBR 37 is formed by alternately stacking insulatinglayers with different refractive indices, e.g., SiO₂/TiO₂ or SiO₂/Nb₂O₅,relatively high-density layers are stacked, and hence the stress in theupper DBR may be increased. Therefore, the upper DBR is easily detachedfrom the layer below it, e.g., the spacer layer 33. Accordingly, if thestress relaxation layer 35 is disposed under the upper DBR 37, it ispossible to prevent the detachment of the upper DBR 37.

Meanwhile, in this exemplary embodiment, the spacer layer 33 may be madeof a single layer, e.g., of silicon nitride or silicon oxide, or may beomitted.

FIG. 4 is a sectional view illustrating an LED chip 104 according to anexemplary embodiment of the present invention.

Referring to FIG. 4, although the horizontal type LED chips 101, 102 and103 have been described as examples in FIG. 1, FIG. 2, and FIG. 3, theLED chip 104 shown in FIG. 4 is a vertical type LED chip. The LED chip104 includes a substrate 51; a semiconductor stacked structure 30including a first conductive semiconductor layer 25, an active layer 27and a second conductive semiconductor layer 29; an upper electrode 41;an additional electrode 43; and a wavelength converting layer 60. Thewavelength converting layer 60 may be spaced apart from thesemiconductor stacked structure 30 by a spacer layer. For example, thespacer layer may include a spacer layer 33 as described with referenceto FIG. 2, or may include a spacer layer 33, a stress relaxation layer35 and/or an upper DBR 37 as described with reference to FIG. 3.Further, the LED chip 104 may include a reflection metal layer 55, abarrier metal layer 57 and a bonding metal 53.

The substrate 51 is distinguished from a growth substrate for growingthe semiconductor layers 25, 27 and 29, and is a secondary substrateattached to the previously grown compound semiconductor layers 25, 27and 29. Although the substrate 51 may be a conductive substrate, e.g., ametal substrate or semiconductor substrate, the present invention is notlimited thereto. That is, the support substrate may be an insulatingsubstrate, e.g., sapphire.

The semiconductor stacked structure 30 is positioned on the substrate51, and includes the first conductive semiconductor layer 25, the activelayer 27 and the second conductive semiconductor layer 29. Here, in thesemiconductor stacked structure 30, the p-type compound semiconductorlayer, i.e., the second conductive semiconductor layer 29 is positionedcloser to the substrate 51 than the n-type compound semiconductor layer,i.e., the first conductive semiconductor layer 25. The semiconductorstacked structure 30 may be positioned on a partial region of thesubstrate 51. That is, the substrate 51 may have a relatively wider areathan the semiconductor stacked structure 30, and the semiconductorstacked structure 30 may be positioned within the region surrounded bythe edge of the substrate 51.

Since the first conductive semiconductor layer 25, the active layer 27and the second conductive semiconductor layer 25 are similar to thesemiconductor layers described with reference to FIG. 1, their detaileddescriptions will be omitted. Meanwhile, the n-type compoundsemiconductor layer 25 having a relatively small resistance ispositioned at the opposite side of the substrate 51 so that the topsurface of the n-type compound semiconductor layer 25 may be configuredto be coarse.

The reflection metal layer 55 may be interposed between the substrate 51and the semiconductor stacked structure 30, and the barrier metal layer57 may be interposed between the substrate 51 and the reflection metallayer 55 so as to surround the reflection metal layer 55. The substrate51 and the barrier metal layer 57 may completely surround the reflectionmetal layer 55, as shown in FIG. 4. Further, the substrate 51 may bebonded to the semiconductor stacked structure 30 through the bondingmetal 53. The reflection metal layer 55 and the barrier metal layer 57may serve as a lower electrode electrically connected to the secondconductive semiconductor layer 29.

Meanwhile, the wavelength converting layer 60 is positioned above thesemiconductor stacked structure 30. Although the wavelength convertinglayer 60 may be positioned above the semiconductor stacked structure 30,the wavelength converting layer may also cover side surfaces of thesemiconductor stacked structure 30. Further, the wavelength convertinglayer 60 may cover side surfaces of the substrate 51.

The spacer layer 33 covers the top surface of the semiconductor stackedstructure 30, and the stress relaxation layer 35 and the upper DBR 37may be sequentially positioned on the spacer layer 33. Since the spacerlayer 33, the stress relaxation layer 35 and the upper DBR 37 may bemade of the same materials as described with reference to FIG. 3, theirdetailed descriptions will be omitted to avoid redundancy. The spacerlayer 33 may also be omitted. The spacer layer 33 may be a DBR asdescribed with reference to the exemplary embodiment shown in FIG. 2. Inthis case, the stress relaxation layer 35 and the upper DBR 37 may beomitted.

Meanwhile, the upper electrode 41 is positioned on the semiconductorstacked structure 30, e.g., the first conductive semiconductor layer 25and electrically connected to the first conductive semiconductor layer25. The additional electrode 43 is positioned on the upper electrode 41.The additional electrode 43 may have the same shape and structure as thefirst or second additional electrode 43 or 44 described with referenceto FIG. 1. The additional electrode 43 is exposed to the outside throughthe wavelength converting layer 60.

FIG. 5 is a sectional view illustrating an LED chip 105 according to anexemplary embodiment of the present invention.

Referring to FIG. 5, the LED chip 105 is similar to the LED chip 101described with reference to FIG. 1, but is different in that thewavelength converting layer 50 is spaced apart from the semiconductorstacked structure 30. That is, a spacer layer 61 is interposed betweenthe wavelength converting layer 50 and the semiconductor stacked layer30.

As the wavelength converting layer 50 is spaced apart from thesemiconductor stacked structure 30, it is possible to prevent the resinor phosphor in the wavelength converting layer 50 from beingdeteriorated by light generated in the active layer 27. The spacer layer61 may also be interposed between the side surfaces of the substrate 21and the wavelength converting layer 50.

The spacer layer 61 may be made of a transparent resin, a siliconnitride film or a silicon oxide film. In order to reduce heattransferred to the phosphor, the thermal conductivity of the spacerlayer 61 may be relatively low. For example, the spacer layer 61 mayhave a thermal conductivity less than 3 W/mK. When the spacer layer 61is made of a transparent resin, TiO₂, SiO₂ or Y₂O₃ may be incorporatedinto the transparent resin so as to control the refractive index of thetransparent resin. TiO₂, SiO₂ or Y₂O₃ may be in powder form, forexample. Further, the spacer layer 61 may be formed into a single- ormulti-layered structure. The refractive index and thickness of aplurality of layers that constitute the spacer layer 61 is controlled,so that the spacer layer 61 can be configured to transmit lightgenerated in the active layer 27 and to reflect light converted in thewavelength converting layer 50 and then incident into the LED chip 105.For example, a DBR to transmit light generated in the active layer orreflect light converted in the wavelength converting layer 50 may beselectively formed by repeatedly stacking layers with differentrefractive indices, e.g., TiO₂ and SiO₂. Further, when the spacer layer61 includes a DBR, a stress relaxation layer 62 may be interposedbetween the semiconductor stacked structure 30 and the DBR so as toprevent the release of the DBR, like the exemplary embodiment of the LEDchip 106 shown in FIG. 6.

FIG. 7 is a sectional view illustrating an LED chip 107 according to anexemplary embodiment of the present invention.

Referring to FIG. 7, the LED chip 107 is almost identical to the LEDchip 105 described with reference to FIG. 5, but is different in that itfurther includes a spacer layer 33, a lower DBR 45 and a metal layer 47.A transparent conductive layer 31 is interposed between the spacer layer33 and the second conductive semiconductor layer 29 of the semiconductorstacked structure 30. The second electrode 42 may be connected to thetransparent conductive layer 31. The spacer layer 61 covers the spacerlayer 33 so that the wavelength converting layer 50 is further spacedapart from the semiconductor stacked structure 30. When the spacer layer61 is a DBR, the stress relaxation layer 62 as shown in FIG. 6 may beinterposed between the spacer layer 61 and the semiconductor stackedstructure 30 so as to prevent the release of the spacer layer 61.

Since the spacer layer 33, the lower DBR 45 and the metal layer 47 areidentical to those described with reference to FIG. 2, their detaileddescriptions will be omitted to avoid redundancy. As described withreference to FIG. 3, the upper DBR 37 and the stress relaxation layer 35may be positioned above the semiconductor stacked structure 30, andthus, the wavelength converting layer 50 can be further spaced apartfrom the semiconductor stacked structure 30.

FIG. 8 is a sectional view illustrating an LED chip 108 according to anexemplary embodiment of the present invention.

Referring to FIG. 8, the LED chip 108 is almost identical to the LEDchip 105 described with reference to FIG. 5, but is different in that atransparent resin 63 is additionally formed on the wavelength convertinglayer 50. That is, the transparent resin 63 covers the wavelengthconverting layer 50. The transparent resin 63 protects the phosphor fromexternal moisture. In order to prevent moisture absorption, thetransparent resin 63 may have a relatively high hardness, e.g., adurometer Shore hardness of 60A or greater. When the spacer layer 61 ismade of a transparent resin, the high-hardness transparent resin 63 mayhave a higher hardness than the transparent resin of the spacer layer61.

In order to control the refractive index of the high-hardnesstransparent resin 63, TiO₂, SiO₂ or Y₂O₃ may be incorporated into thehigh-hardness transparent resin 63. TiO₂, SiO₂ or Y₂O₃ may be in powderform.

FIG. 9 is a sectional view illustrating an LED chip 109 according to astill further embodiment of the present invention.

Referring to FIG. 9, the LED chip 109 is almost identical to the LEDchip 108 described with reference to FIG. 8, but is different in that itfurther includes a spacer layer 33, a lower DBR 45 and a metal layer 47.A transparent conductive layer 31 is interposed between the spacer layer33 and the second conductive semiconductor layer 29 of the semiconductorstacked structure 30. The second electrode 42 may be connected to thetransparent conductive layer 31. The spacer layer 61 covers the spacerlayer 33 so that the wavelength converting layer 50 is further spacedapart from the semiconductor stacked structure 30.

Since the spacer layer 33, the lower DBR 45 and the metal layer 47 areidentical to those described with reference to FIG. 2, their detaileddescriptions will be omitted to avoid redundancy. As described withreference to FIG. 3, the upper DBR 37 and the stress relaxation layer 35may be positioned above the semiconductor stacked structure 30, andthus, the wavelength converting layer 50 can be further spaced apartfrom the semiconductor stacked structure 30.

FIG. 10 is a sectional view illustrating an LED chip 110 according to anexemplary embodiment of the present invention.

Referring to FIG. 10, the LED chip 110 is similar to the LED chip 101described with reference to FIG. 1, but is different in that the topsurface of the first additional electrode 43 is positioned lower thanthat of the second additional electrode 44.

Accordingly, the top surface of a wavelength converting layer 70 has astepped shape in the vicinity of the first additional electrode 43. Thewavelength converting layer 70 having such a stepped shape may be formedusing a mold specially manufactured along the surface shape of thesemiconductor stacked structure.

FIG. 11 is a sectional view illustrating an LED chip 111 according to anexemplary embodiment of the present invention.

Referring to FIG. 11, the LED chip 111 is similar to the LED chip 110described with reference to FIG. 10, but is different in that it furtherincludes a spacer layer 33, a lower DBR 45 and a metal layer 47. Atransparent conductive layer 31 is interposed between the spacer layer33 and the second conductive semiconductor layer 29 of the semiconductorstacked structure 30. The second electrode 42 may be connected to thetransparent conductive layer 31.

Since the spacer layer 33, the lower DBR 45 and the metal layer 47 areidentical to those described with reference to FIG. 2, their detaileddescriptions will be omitted to avoid redundancy. As described withreference to FIG. 3, the stress relaxation layer 35 and the upper DBR 37may be interposed between the wavelength converting layer 70 and thesemiconductor stacked structure 30.

FIG. 12 is a sectional view illustrating an LED chip 112 according to anexemplary embodiment of the present invention.

Referring to FIG. 12, the LED chip 112 is similar to the LED chip 110described with reference to FIG. 10, but is different in that thewavelength converting layer 70 is spaced apart from the semiconductorstacked structure 30. That is, a spacer layer 71 is interposed betweenthe wavelength converting layer 70 and the semiconductor stackedstructure as described with reference to FIG. 5. As the wavelengthconverting layer 70 is spaced apart from the semiconductor stackedstructure, it is possible to prevent the resin or phosphor in thewavelength converting layer 70 from being deteriorated by lightgenerated in the active layer 27. The spacer layer 71 may also beinterposed between the side surfaces of the substrate 21 and thewavelength converting layer 70.

When the spacer layer 71 includes a DBR, the stress relaxation layer 62described with reference to FIG. 6 may be interposed between the spacerlayer 71 and the semiconductor stacked structure 30.

FIG. 13 is a sectional view illustrating an LED chip 113 according to anexemplary embodiment of the present invention.

Referring to FIG. 13, the LED chip 113 is similar to the LED chip 112described with reference to FIG. 12, but is different in that it furtherincludes a spacer layer 33, a lower DBR 45 and a metal layer 47. Atransparent conductive layer 31 is interposed between the spacer layer33 and the second conductive semiconductor layer 29 of the semiconductorstacked structure 30. The second electrode 42 may be connected to thetransparent conductive layer 31. The spacer layer 71 covers the spacerlayer 33 so that the wavelength converting layer 70 is further spacedapart from the semiconductor stacked structure 30.

Since the spacer layer 33, the lower DBR 45 and the metal layer 47 areidentical to those described with reference to FIG. 2, their detaileddescriptions will be omitted to avoid redundancy. As described withreference to FIG. 3, the upper DBR 37 and the stress relaxation layer 35may be positioned above the semiconductor stacked structure 30, andthus, the wavelength converting layer 70 can be further spaced apartfrom the semiconductor stacked structure 30.

FIG. 14 is a sectional view illustrating an LED chip 114 according to anexemplary embodiment of the present invention.

Referring to FIG. 14, the LED chip 114 is similar to the LED 112described with reference to FIG. 12, but is different in that atransparent resin 73 is additionally formed on the wavelength convertinglayer 70. That is, the transparent resin 73 covers the wavelengthconverting layer 70. The transparent resin 73 protects the phosphor fromexternal moisture. In order to prevent moisture absorption, thetransparent resin 73 may have a relatively high hardness, e.g., adurometer Shore hardness of 60A or greater. When the spacer layer 71 ismade of a transparent resin, the high-hardness transparent resin 73 mayhave a higher hardness than the transparent resin of the spacer layer71.

In order to control the refractive index of the high-hardnesstransparent resin 73, TiO₂, SiO₂ or Y₂O₃ may be incorporated into thehigh-hardness transparent resin 73.

FIG. 15 is a sectional view illustrating an LED chip 115 according to anexemplary embodiment of the present invention.

Referring to FIG. 15, the LED chip 115 is similar to the LED chip 114described with reference to FIG. 14, but is different in that it furtherincludes a spacer layer 33, a lower DBR 45 and a metal layer 47. Atransparent conductive layer 31 is interposed between the spacer layer33 and the second conductive semiconductor layer 29 of the semiconductorstacked structure 30. The second electrode 42 may be connected to thetransparent conductive layer 31. The spacer layer 71 covers the spacerlayer 33 so that the wavelength converting layer 70 is further spacedapart from the semiconductor stacked structure 30.

Since the spacer layer 33, the lower DBR 45 and the metal layer 47 areidentical to those described with reference to FIG. 2, their detaileddescriptions will be omitted to avoid redundancy. As described withreference to FIG. 3, the upper DBR 37 and the stress relaxation layer 35may be positioned above the semiconductor stacked structure 30, andthus, the wavelength converting layer 70 can be further spaced apartfrom the semiconductor stacked structure 30.

FIG. 16 is a sectional view illustrating an LED chip 116 according to anexemplary embodiment of the present invention.

Referring to FIG. 16, the LED chip 116 is almost similar to the LED chip101 described with reference to FIG. 1, but is different in that aplurality of semiconductor stacked structures 30 are positioned on thesubstrate 21. The plurality of semiconductor stacked structures may beelectrically connected to one another by wires 83. Each of the wires 83connects a first conductive semiconductor layer 25 of one of thesemiconductor stacked structures 30 to a second conductive semiconductorlayer 29 of another of the semiconductor stacked structures 30 adjacentto said one of the semiconductor stacked structures 30, thereby forminga serial array. Such serial arrays may be connected in parallel or inreverse parallel.

Meanwhile, an insulating layer 81 may be interposed between thesemiconductor stacked structures and the wire 83 so as to prevent thefirst and second conductive semiconductor layers 25 and 29 of thesemiconductor stacked structures from being short-circuited by the wire83. The insulating layer 81 also serves as a spacer layer to allow thesemiconductor stacked structures 30 and the wavelength converting layer50 to be spaced apart from each other.

Meanwhile, the first and second electrodes 41 and 42 may be positionedon different semiconductor stacked structures 30, respectively. In thisexemplary embodiment, the positions on which the first and secondelectrodes 41 and 42 are formed are not particularly limited. Forexample, the first and second electrodes 41 and 42 may all be formed onthe substrate 21, or may all be formed on the first or second conductivesemiconductor layers 25 or 29. In this case, the first and secondelectrodes 41 and 42 may be connected to different semiconductor stackedstructure 30 through the wire 83, respectively. The first and secondadditional electrodes 43 and 44 are disposed on the first and secondelectrodes 41 and 42, respectively.

The wavelength converting layer 50 covers the plurality of semiconductorstacked structures 30. The wavelength converting layer 50 may also coverthe side surfaces of the substrate 21. As described with reference toFIG. 5, the wavelength converting layer 50 may be spaced apart from thesemiconductor stacked structure by the spacer layer 61.

FIG. 17 is a sectional view illustrating an LED chip 117 according to anexemplary embodiment of the present invention.

Referring to FIG. 17, the LED chip 117 is similar to the LED chip 116described with reference to FIG. 16, but is different in that it furtherincludes a second insulating layer 85, a lower DBR 45 and a metal layer47. The side surfaces of each of the semiconductor stacked structures 30are configured to be inclined so that the wires 83 may be easily formed.A transparent conductive layer 31 is positioned between the insulatinglayer 81 and each of the semiconductor stacked structures 30. Thetransparent conductive layer 31 is in ohmic contact with the secondconductive semiconductor layer 29. Each of the wires 83 connects a firstconductive semiconductor layer 25 of one of the semiconductor stackedstructures 30 to a second conductive semiconductor layer 29 of anotherof the semiconductor stacked structures 30 adjacent to said one of thesemiconductor stacked structures 30, thereby forming a serial array.Such serial arrays may be connected in parallel or in reverse parallel.

Meanwhile, the insulating layer 81 may cover the transparent conductivelayer 31, and may further cover the side surfaces of the semiconductorstacked structures 30. The second insulating layer 85 may cover thesemiconductor stacked structures 30 and the wires 83 so as to protectthe semiconductor stacked structures 30 and the wires 83, and the secondinsulating layer 85 covers the insulating layer 81. Each of the firstand second insulating layers 81 and 85 may be formed of a layer made ofthe same material, e.g., a silicon oxide film or a silicon nitride film,and may be formed into a single-layered structure. In this case, thesecond insulating layer 85 may be relatively thinner than the insulatinglayer so as to prevent the second insulating layer 85 from beingreleased from the insulating layer 81.

Alternatively, the insulating layer 81 and/or the second insulatinglayer 85 may be implemented with a DBR formed by alternately stackinginsulating layers with different refractive indices, like the spacerlayer 33 described with reference to FIG. 2. As described in FIG. 2, theDBR is configured to transmit light generated in the active layer 27 andto reflect light converted in the wavelength converting layer 50. Thesecond insulating layer 85 may be formed with a DBR, while theinsulating layer 81 may be formed with a stress relaxation layer such asan SOG or a porous silicon oxide film.

The wavelength converting layer 50 is positioned on the secondinsulating layer 85, and the insulating layer 81 and the secondinsulating layer 85 serve as spacer layers. In addition, the spacerlayer 61 as described with reference to FIG. 5 may be interposed betweenthe plurality of semiconductor stacked structures 30 and the wavelengthconverting layer 50. As described with reference to FIG. 8, thehigh-hardness transparent resin 63 may cover the wavelength convertinglayer 50.

FIG. 18 is a sectional view illustrating an LED chip 118 according to anexemplary embodiment of the present invention.

Referring to FIG. 18, the LED chip 118 is similar to the LED chip 117described with reference to FIG. 17, but is different in that it furtherincludes a stress relaxation layer 87 and an upper DBR 89.

That is, the upper DBR 89 may be positioned between the plurality ofsemiconductor stacked structures 30 and the wavelength converting layer50. In addition, the stress relaxation layer 87 may be positionedbetween the upper DBR 89 and the plurality of semiconductor stackedstructures 30. The upper DBR 89 may be formed by alternately stackinginsulating layers with different refractive indices, like the upper DBR37 described with reference to FIG. 3. The stress relaxation layer 87may be formed with an SOG or a porous silicon oxide film, like thestress relaxation layer 35 of FIG. 3. The upper DBR 89 and the stressrelaxation layer 87 also serve as spacer layers to allow the wavelengthconverting layer 50 to be spaced apart from the semiconductor stackedstructure 30.

In this exemplary embodiment, each of the insulating layer 81 and thesecond insulating layer 85 may be formed into a single-layeredstructure, and the second insulating layer 85 may be omitted.

In the aforementioned exemplary embodiments, the phosphor may be ayttrium aluminum garnet (YAG)- or terbium aluminum garnet (TAG)-basedphosphor, a silicate-based phosphor or a nitride- or oxynitride-basedphosphor. Although the wavelength converting layer 50, 60 or 70 maycontain the same kind of phosphor, the present invention is not limitedthereto. That is, the wavelength converting layer may contain two ormore kinds of phosphors. Although it has been illustrated and describedthat the wavelength converting layer 50, 60 or 70 is a single layer, aplurality of wavelength converting layers may be used, and differentphosphors may be contained in the plurality of wavelength convertinglayers, respectively.

FIG. 19 is a sectional view illustrating an LED package having the LEDchip 101 mounted therein according to an exemplary embodiment of thepresent invention.

Referring to FIG. 19, the LED package includes the LED chip 101, a mount91 for mounting the LED chip 101 thereon. The LED package furtherincludes bonding wires 95 and a lens 97.

The mount 91 may be, for example, a printed circuit board, a lead frame,a ceramic substrate or the like, and includes lead terminals 93 a and 93b. The first and second additional electrodes (43 and 44 in FIG. 1,respectively) of the LED chip 101 are electrically connected to the leadterminals 93 a and 93 b through the bonding wires 95, respectively.

Meanwhile, the lens 97 covers the LED chip 101. The lens 97 adjusts adirectional angle of the light emitted from the LED chip 101 so that thelight is emitted in a desired direction. Since the wavelength convertinglayer 50 is formed in the LED chip 101, the lens 97 does not necessarilycontain a phosphor.

Although the LED package with the built-in LED chip 101 mounted thereinhas been described in the present exemplary embodiment, any of the LEDchips 101 to 117 as described with reference to FIGS. 2 to 17 may bemounted in the LED package.

Hereinafter, a method of fabricating an LED chip according to exemplaryembodiments of the present invention will be described in detail.

FIG. 20 shows sectional views illustrating a method of fabricating theLED chip 101 according to an exemplary embodiment of the presentinvention.

Referring to FIG. 20( a), bare chips 150 are arranged on a supportsubstrate 121. The bare chips 150 may be arranged at an equal intervalon the support substrate 121. As described in FIG. 1, each of the barechips 150 includes a substrate 21; a semiconductor stacked structure 30including a first conductive semiconductor layer 25, an active layer 27and a second conductive semiconductor layer 29; a first electrode 41;and a second electrode 42. A buffer layer 23 may be interposed betweenthe first conductive semiconductor layer 25 and the substrate 21. Thatis, each bare chip 150 corresponds to a portion of the LED chip 101shown in FIG. 1 in which the first and second additional electrodes 43and 44 and the wavelength converting layer 50 are excluded, and detaileddescriptions of the respective components in each bare chip 150 will beomitted to avoid redundancy.

The support substrate 121 supports the bare chips 150 so that the barechips 150 maintain an equal interval therebetween. The support substrate121 may be, for example, a substrate made of glass, ceramic, sapphire,GaN, Si or the like.

Referring to FIG. 20( b), first and second additional electrodes 43 and44 are formed in each of the bare chips 150. For example, the first andsecond additional electrodes 43 and 44 may be formed using chemicalvapor deposition (CVD), sputtering, plating, solder ball or the like.The first and second additional electrodes 43 and 44 may be made of amaterial with electric conductivity, such as Au, Ag, Cu, W, Ni or Al, oralloys thereof. Accordingly, the first and second additional electrodes43 and 44 as described with reference to FIG. 1 may be formed on each ofthe bare chips 150.

Referring to FIG. 20( c), a wavelength converting layer 50 for coveringthe bare chips 150 and the first and second additional electrodes 43 and44 is formed on the support substrate 50. The wavelength convertinglayer 50 may contain a phosphor, and may further contain TiO₂, SiO₂ orY₂O₃ so as to control its refractive index. The wavelength convertinglayer 50 is configured to be thick enough to cover the first and secondadditional electrodes 43 and 44. The wavelength converting layer 50 maybe formed using various application methods including injection molding,transfer molding, compression molding, printing and the like.

Referring to FIG. 20( d), the support substrate 121 is removed after thewavelength converting layer 50 is formed. A release film (not shown) maybe formed on the support substrate 121 so that the support substrate 121is easily removed. The release film may be a kind of film which may bereleased by, for example, heat or light such as ultraviolet light. Thus,the support substrate 121 can be easily removed by applying heat to therelease film or irradiating light such as ultraviolet light onto therelease film.

After the support substrate 121 is removed, the bare chips 150 are fixedto one another by the wavelength converting layer 50, and may beattached on a separate support body.

Referring to FIG. 20( e), the first and second additional electrodes 43and 44 are exposed by removing an upper portion of the wavelengthconverting layer 50. The upper portion of the wavelength convertinglayer 50 may be removed by a physical method using grinding, cutting orlaser, or may be removed by a chemical method using etching or the like.Further, the upper portion of the wavelength converting layer 50 may beremoved so that the top surfaces the first and second additionalelectrodes 43 and 44 are flush with the wavelength converting layer 50.

Referring to FIG. 20( f), individual LED chips 101 shown in FIG. 1 arecompleted by sawing the wavelength converting layer 50 filled in spacesbetween the bare chips 150. The wavelength converting layer 50 may besawed using blade or laser. Each of the individual LED chips 101 exposesthe first and second additional electrodes 43 and 44, and has thewavelength converting layer 50 for covering the side surfaces of thesubstrate 21 and the top surface of the semiconductor stacked structure.

Although it has been described in the present exemplary embodiment thatthe first and second additional electrodes 43 and 44 are formed on thesupport substrate 121, the present invention is not limited thereto.That is, the first and second additional electrodes 43 and 44 may beformed on each of the bare chips before the bare chips are arranged onthe support substrate 121.

The spacer layer (61 in FIG. 5) may be first formed on the bare chips150 arranged on the support substrate 121 before the first and secondadditional electrodes 43 and 44 are formed. Further, the stressrelaxation layer (62 in FIG. 6) may be formed before the spacer layer isformed. Subsequently, the first and second electrodes 41 and 42 areexposed by pattering the spacer layer, and the first and secondadditional electrodes 43 and 44 may be formed on the first and secondelectrodes 41 and 42, respectively.

Although it has been described in the present exemplary embodiment thatthe support substrate 121 is removed before the upper portion of thewavelength converting layer 50 is removed, the support substrate 121 maybe removed after the upper portion of the wavelength converting layer 50is removed or after the wavelength converting layer 50 is sawed usingblade, laser or the like.

Meanwhile, each of the bare chips 150 may include a spacer layer 33, alower DBR 45 and a metal layer 47 as described with reference to FIG. 2,and may further include an upper DBR 37 and a stress relaxation layer 35as described with reference to FIG. 3. Although each bare chip 150 mayinclude a single semiconductor stacked structure 30 as described withreference to FIG. 1, the present invention is not limited thereto. Thatis, each bare chip 150 may include a plurality of semiconductor stackedstructures 30 as described with reference to FIG. 16, FIG. 17, and FIG.18, and may further include an insulating layer 81, a second insulatinglayer 85, a stress relaxation layer 87 and a DBR 89. As such, the LEDchips 116 to 118 as shown in FIG. 16, FIG. 17, and FIG. 18 can befabricated.

Although it has been described in the present exemplary embodiment thatthe LED chip with the wavelength converting layer 50 formed on each barechip 150 is fabricated, various transparent coating layers for changingoptical characteristics as well as the wavelength converting layer 50may be formed on each bare chip 150 using a method similar to the methodof forming the wavelength converting layer 50 according to thisembodiment. The transparent coating layers may contain various materialsfor improving optical characteristics, e.g., a diffusion material.

Hereinafter, an LED according to an exemplary embodiment of the presentinvention will be described with reference to FIG. 21 and FIG. 22.

FIG. 21 is a top plan view illustrating an LED according to an exemplaryembodiment of the present invention. FIG. 22 is a sectional view of theLED taken along line C-C′ of FIG. 21.

Referring to FIG. 21 and FIG. 22, the LED according to the presentexemplary embodiment may include a submount substrate 1000; a bare chip200; an adhesive member 300; first and second electrodes 210 and 220formed on an upper portion of the bare chip 200; first and secondadditional electrodes 410 and 420; and a wavelength converting layer500.

Here, the submount substrate 1000 is used to mount and move the barechip 200, and is distinguished from a growth substrate for growing asemiconductor stacked structure of the bare chip 200, which will bedescribed later. An electrode (not shown) may be formed or may not beformed on the submount substrate 1000. Although the submount substrate1000 may be, for example, a printed circuit board, a lead frame or aceramic substrate, the present invention is not limited thereto. Thesubmount substrate 1000 has a top surface, a bottom surface and sidesurfaces to connect the top and bottom surfaces to each other. Firstslits 1110 and second slits 1120 may be formed along the circumferenceof a region of the submount substrate 1000 on which the bare chip 200 ismounted.

The first and second slits 1110 and 1120 are formed in the submountsubstrate 1000 before the bare chip 200 is mounted on the submountsubstrate 1000, in consideration of the position at which the bare chip200 is to be mounted on the submount substrate 1000 and the size of thebare chip 200. As such, the first and second slits 1110 and 1120 allowthe interval between the first and second slits 1110 and 1120 and thebare chip 200 to be constantly maintained. Accordingly, when the barechip 200 is mounted on the submount substrate 1000 using, for example, ametal bonding method as will be described later, the drift of the meltedmetal may be limited by the slits 1110 and 1120. As a result, the barechip 200 may not be misaligned, and may be disposed at its correctposition.

Although the first and second slits 1110 and 1120 may be formed, forexample, in the shape of an opening which passes through the submountsubstrate 1000, the present invention is not limited thereto. That is,according to exemplary embodiments, the first and second slits 1110 and1120 may be formed in the shape of a concave pattern formed using, e.g.,an etching scheme.

When the first and second slits 1110 and 1120 are formed in the shape ofan opening, the wavelength converting layer 500 passes through theopenings of the first slits 1110 so that the wavelength converting layer500 is formed not only on the top surface of the submount substrate 1000but also on inner side surfaces of the submount substrate 1000 asindicated in region A of FIG. 22. As such, the submount substrate 1000and the bare chip 200 may be fixed to each other by the wavelengthconverting layer 500.

The shapes of the openings of the first and second slits 1110 and 1120may be identical to or different from each other. Although the openingsof the first and second slits 1110 and 1120 may be formed in a shapesimilar to a rectangle with rounded corners, the present invention isnot limited thereto. That is, the openings of the first and second slits1110 and 1120 may be formed in a shape extended along side surfaces ofthe bare chip 200. Meanwhile, FIG. 21 shows the state in which thesubmount substrate 1000 is cut for each chip when the second slit 1120is formed to be overlapped with a dicing line 1140 (see FIG. 24), andtherefore, only the half shapes of the second slits 1120 have beenshown, unlike the first slits 1110. When the position of the dicing line1140 is controlled, the second slits 1120 may be formed similar to thefirst slits 1110. The adhesive member 300 serves to attach the bare chip200 to the top surface of the submount substrate 1000. Although when thebare chip 200 has, for example, a horizontal type structure, a bottomsurface of the growth substrate (not shown) on which a semiconductorlayer of the bare chip 200 is formed and a top surface of the submountsubstrate 1000 may be attached to each other through the adhesive member300, the present invention is not limited thereto. The adhesive member300 may be prepared using silicon paste, metal paste, epoxy paste or thelike. However, the present invention is not limited to the specific kindof adhesive member. That is, the bare chip 200 may be mounted on thesubmount substrate 1000 through metal bonding using a metal such asAuSn.

Although the bare chip 200 as described above is not illustrated for thesake of simplicity, the bare chip 200 may be an LED chip in which aGaN-based semiconductor stacked structure including a first conductivesemiconductor layer, an active layer and a second conductivesemiconductor layer is formed. Specifically, the semiconductor stackedstructure may include, for example, n-type and p-type layers made of aGaN film and an active layer made of an InGaN film. The semiconductorstacked structure is generally grown on a growth substrate (not shown),and the growth substrate may be formed using a sapphire (Al₂O₃)substrate, a silicon carbide (SiC) substrate, a silicon (Si) substrate,a zinc oxide (ZnO) substrate, a gallium arsenide (GaAs) substrate, agallium phosphide (GaP) substrate, or the like. When the bare chip 200has a vertical type structure, the growth substrate may be separatedfrom the semiconductor stacked structure through, e.g., a laser lift-off(LLO) process.

The present invention is not limited to a specific structure of the barechip, such as a horizontal or vertical type structure, but the followingdescription will be directed mainly to the horizontal type bare chip.Since the structure of the bare chip 200 is identical to that of ageneral GaN-based LED, its detailed description will be omitted.

The first electrode 210 and the second electrode 220 are electricallyconnected to the first and second conductive semiconductor layers (notshown) of the bare chip 200, respectively. For example, each of thefirst and second electrodes may include Ti, Cu, Ni, Al, Au or Cr, andmay be made of an alloy of these. The first and second electrodes 210and 220 may be configured to have a thickness of about 10 μm to 200 μm.Although FIG. 21 shows that the number of each of the first and secondelectrodes 210 and 220 formed on the top surface of the bare chip istwo, the number or position of each of the first and second electrodes210 and 220 is not limited to any specific embodiment illustratedherein. That is, according to the kind of the bare chip 200, all thefirst and second electrodes 210 and 220 may be formed on the top surfaceof the bare chip 200 when the bare chip 200 has a horizontal typestructure. Alternatively, any one of the first and second electrodes 210and 220 may be omitted when the bare chip 200 has a vertical typestructure. When all the first and second electrodes 210 and 220 areformed on the top surface of the bare chip, only one first electrode 210and one second electrode 220 may be formed opposite to each other on thetop surface of the bare chip 200, unlike that shown in FIG. 21. That is,as the area of the bare chip 200 itself becomes large, the number ofeach of the first and second electrodes 210 and 220 formed on top of thebare chip may be two as shown in FIG. 21. However, in a general case,the number of the first and second electrodes 210 and 220 formed on topof the bare chip may be one, and the position of each of the first andsecond electrodes 210 and 220 may be changed depending on the horizontalor vertical type structure. The following description will be directedmainly to the structure of FIG. 22.

The first additional electrode 410 and the second additional electrode420 may be formed on the respective first and second electrodes 210 and220 with a thickness of at least 100 μm, for example, using a conductivemetallic material such as Au, Cu, Ag or Al. The first and secondadditional electrodes 410 and 420 may be formed by a fabrication methodusing chemical vapor deposition (CVD), e-beam, sputtering, plating,solder ball, or the like. Depending on embodiments, the first and secondadditional electrodes 410 and 420 may be formed by applying aphotosensitive material and then exposing and developing the appliedphotosensitive material, and therefore, the present invention is notlimited to the specific forming method of the first and secondadditional electrodes 410 and 420.

The first and second additional electrodes 410 and 420 may be narrowerthan the first and second electrodes 210 and 220, respectively. That is,the first and second additional electrodes 410 and 420 are limited tothe top portions of the first and second electrodes 210 and 220,respectively. The first addition electrode 410 and the second additionalelectrode 420 may have shapes in which their widths are narrow as theyextend from the first and second electrodes 210 and 220, respectively.Through such shapes, the first and second additional electrodes 410 and420 can be stably attached to the respective first and second electrodes210 and 220, which may be advantageous in a subsequent process such as awire bonding process. The ratio of height to bottom surface area in eachof the first and second additional electrodes 410 and 420 may be limitedwithin a predetermined range so that the first and second additionalelectrodes 410 and 420 can be stably maintained on the first and secondelectrodes 210 and 220, respectively.

The wavelength converting layer 500 is formed by containing a phosphorin epoxy or silicon or by using only a phosphor. The wavelengthconverting layer 500 uses light generated in the active layer (notshown) of the bare chip 200 as an excitation source to convert thewavelength of the light, and then serves to emit the converted lightwith the wavelength converted.

Here, the kind of the phosphor is not particularly limited, and allmaterials for wavelength conversion, known in the art, may be used. Forexample, the phosphor may include at least one selected from the groupconsisting of (Ba, Sr, Ca)₂SiO₄:Eu²⁺, YAG ((Y, Gd)₃(Al, Ga)₅O₁₂:Ce³⁺)based phosphor, TAG((Tb, Gd)₃(Al, Ga)₅O₁₂:Ce³⁺) based phosphor, (Ba, Sr,Ca)₃SiO₅:Eu²⁺, (Ba, Sr, Ca)MgSi₂O₆:Eu²⁺, Mn²⁺, (Ba, Sr,Ca)₃MgSi₂O₈:Eu²⁺, Mn²⁺, and (Ba, Sr, Ca)MgSiO₄:Eu²⁺, Mn²⁺. However, thepresent invention is not limited thereto.

According to the present exemplary embodiment, the wavelength convertinglayer 500 may be configured to have a uniform thickness not only on thetop surface (region indicated by dotted line in FIG. 21) of the barechip 200 but also on the side surfaces of the bare chip 200. As will bedescribed later, the wavelength converting layer 500 with a flat topsurface may be formed in a region except the top surfaces (whole orportion) of the first and second additional electrodes 410 and 420 byusing a mold. The first and second electrodes 410 and 420 are exposed tothe outside of the LED by passing through the wavelength convertinglayer 500, so that wire bonding can be easily performed in a packagingoperation. Although the wavelength converting layer 500 is formed at achip level, it is unnecessary to perform an additional process ofexposing electrodes for the purpose of wire bonding.

Further, the wavelength converting layer 500 may have a refractiveindex, e.g., ranging from 1.4 to 2.0, and TiO₂, SiO₂ or Y₂O₃ may beincorporated into the wavelength converting layer 500 so as to controlthe refractive index.

Meanwhile, as shown in FIG. 22, the top surface of the first additionalelectrode 410 may be positioned to be flush with that of the secondadditional electrode 420. Thus, when the first conductive semiconductorlayer is exposed by removing portions of the second conductivesemiconductor layer and the active layer in the bare chip 200 as ahorizontal type LED, the first additional electrode 410 electricallyconnected to the first conductive semiconductor layer may be configuredto be longer than the second additional electrode 420 electricallyconnected to the second conductive semiconductor layer.

According to the present exemplary embodiment, since the wavelengthconverting layer 500 covers not only the top surface of the bare chip200 but also the side surfaces of the bare chip 200, the LED can performwavelength conversion not only with respect to light emitted through thetop surface of the semiconductor stacked structure, as described in theexemplary embodiments above, but also with respect to light emittedthrough the side surfaces of the semiconductor stacked structure.

FIG. 23 is a view showing a submount having a plurality of LEDs formedthereon according to an exemplary embodiment of the present invention.FIG. 24 is an enlarged view of a region indicated by a circle in FIG.23.

According to the present exemplary embodiment, a plurality of bare chips200 are mounted in a matrix form on one submount substrate 1000, and thewavelength converting layer 500 is formed on top surfaces of theplurality of bare chips 200 using a mold. Then, the submount substrateis diced into individual chips. If the second slits 1120 are formed tobe overlapped with the dicing line 1140, such a dicing process can beeasily performed.

Meanwhile, slits 1130 for chip separation may be further formed in thesubmount substrate 1000 according to an exemplary embodiment of thepresent invention, in addition to the aforementioned first and secondslits 1110 and 1120. That is, if the submount substrate 1000 is cut in alateral direction (X-direction) along the dicing lines 1140, LEDs may beseparated as individual chips by the slits 1130 for chip separationwhich are formed on the submount substrate 1000 at a predeterminedinterval in a longitudinal direction (Y-direction).

Thus, according to the present exemplary embodiment, a plurality oflight emitting devices can be simultaneously fabricated by mounting aplurality of bare chips on one substrate, forming a wavelengthconverting layer on top surfaces of all the bare chips through the sameprocess, and then cutting the substrate into individual chips. Thus, itis possible to decrease fabrication time and to reduce fabrication costthrough mass production.

Hereinafter, an LED and a method of fabricating a package having thesame will be described in detail with reference to FIGS. 25 and 26.

FIG. 25 is a flowchart illustrating a method of fabricating an LEDpackage according to an exemplary embodiment of the present invention.FIG. 26 shows sectional views sequentially illustrating processes offabricating the LED package according to the embodiment of the presentinvention. The processes of FIG. 25 may be performed at the same time orat different times. If necessary, the order of the processes may bechanged, and a specific process may be omitted. Therefore, the presentinvention is not limited to the order shown in these figures.

First, as shown in FIG. 26( a), a submount substrate 1000 is provided(S1). As described above, a plurality of first and second slits 1110 and1120 may be formed in the submount substrate 1000 along thecircumference of a region of the submount substrate 1000 on which a barechip 200 is to be mounted (see FIG. 24). Slits 1130 for chip separationmay be previously formed so that even if the submount substrate 1000 iscut only in the X-direction in a subsequent dicing process, LEDs may beseparated as individual chips.

Subsequently, as shown in FIG. 26( b), a plurality of bare chips 200 aremounted in a matrix form on the submount substrate 1000 (S2). Here, thebare chip 200 may be attached to a top surface of the submount substrate1000 by using an adhesive member 300, or by using a metal bonding methodusing, e.g., AuSn or the like. In mounting the bare chips 200, the barechips 200 are not misaligned due to the first and second slits 1110 and1120 but may be arranged at desired positions. At this time, first andsecond electrodes 210 and 220 respectively electrically connected tofirst and second conductive semiconductor layers (not shown) may beformed on the top surface of the bare chip 200.

Subsequently, as shown in FIG. 26( c), first and second additionalelectrodes 410 and 420 are formed on top of the first and secondelectrode 210 and 220, respectively (S3). The first and secondadditional electrodes 410 and 420 may be formed, for example, using aconductive metallic material such as Au, Cu, Ag or Al. The first andsecond additional electrodes 410 and 420 may be formed by a fabricationmethod using CVD, e-beam, sputtering, plating, solder balls or the like.Depending on embodiments, the first and second additional electrodes maybe formed by applying a photosensitive material and then exposing anddeveloping the applied photosensitive material.

Subsequently, a wavelength converting layer 500 is formed on the topsurface and side surfaces of each of the bare chips 200 (S4). Accordingto the present exemplary embodiment, as shown in FIG. 26( d), while thesubmount substrate 1000 with the bare chips 200 mounted thereon isclamped with the mold 650 so that the top surfaces of the first andsecond additional electrodes 410 and 420 are pressured and one surfaceof a mold 650 are closely adhered to the top surfaces of the first andsecond additional electrodes 410 and 420, thereby preventing a spacefrom being generated, a mixture of phosphor and resin is injected into amold internal space 600 and then the resin is cured to form thewavelength converting layer 500 (FIG. 26( e)). At this time, the shapesof the additional electrodes 410 and 420 are changed due to the force ofthe mold 650 to pressurize the additional electrodes 410 and 420, sothat the heights of the additional electrodes can be identical to eachother by the mold even though their heights are formed to be slightlydifferent from each other. Further, the gap between the mold and theadditional electrodes 410 and 420 cannot be produced.

Depending on embodiments, the height of the mold may be controlled notonly to be identical to the entire height of the bare chip 2000 but alsoto be lower than the entire height of the bare chip 200 having theadditional electrodes 410 and 420. In FIG. 26( e), only the single barechip 200 has been illustrated as a reference. However, practically, thewavelength converting layer 500 may be simultaneously formed on the topsurfaces of the plurality of bare chips by using a single mold withrespect to the whole of the plurality of bare chips 200 arranged in amatrix form in FIG. 23 and FIG. 24.

Subsequently, the submount substrate 1000 having the wavelengthconverting layer 500 formed thereon is cut along the dicing lines 1140,thereby separating LEDs as individual chips (S5). Since openings of theslits 1130 for chip separation are extended long in a Y-axis directionin regions between chips, it is sufficient to perform a cuttingoperation only in an X-axis direction. Thus, the dicing process can besimplified, and processing time can be reduced.

Subsequently, as shown in FIG. 27, after each of the LEDs is mounted ona substrate 1500 for packaging, bonding wires 800 are electricallyconnected to the respective first and second additional electrodes 410and 420 so that electric power can be applied to the LED, and a lens 700to encapsulate the LED is formed so as to protect the LED from theoutside (S6).

That is, FIG. 27 is a sectional view illustrating the LED package havingthe LED mounted therein according to the present exemplary embodiment.Referring to FIG. 27, the LED package may include a substrate 1500 forpackaging to which the submount substrate 1000 having the bare chip 200mounted thereon is attached, bonding wires 800 electrically connected tothe respective first and second additional electrodes 410 and 420 formedon the bare chip 200, and a lens 700 for encapsulating the bare chip200.

Unlike the submount substrate 1000, the substrate 1500 for packaging isa substrate provided to supply electric power to the bare chip 200, andmay be, for example, a printed circuit board, a lead frame, a ceramicsubstrate or the like. However, the present invention is not limitedthereto. The substrate for packaging may include lead terminals forpower supply (not shown). Thus, the first and second additionalelectrodes 410 and 420 may be electrically connected to the leadterminals through the bonding wires 800, respectively.

Meanwhile, the lens 700 is configured to encapsulate the submountsubstrate 1000 having the wavelength converting layer 500 formedthereon, i.e., for covering the entire bare chip 200, so that lightgenerated in the bare chip 200 can be emitted in a desired direction byadjusting the directional angle of the light. According to thisembodiment, since the wavelength converting layer 500 is formed on thebare chip 200, the lens 700 does not necessarily contain a phosphor. Insome cases, the lens may contain a phosphor which is different from thephosphor contained in the wavelength converting layer 500.

Thus, according to the present exemplary embodiment, as the LED ispackaged using each of the bare chips 200 mounted on the submountsubstrate 1000, the package design can be more freely performed.Further, the packaging operation is simplified, so that operationalefficiency can be enhanced.

Hereinafter, an LED according to an exemplary embodiment of the presentinvention will be described with reference to FIG. 28.

Unlike the aforementioned exemplary embodiment, the LED of FIG. 22 has,for example, a structure in which the wavelength converting layer 500comes in contact with the semiconductor stacked structure of the barechip 200. However, the LED shown in FIG. 28 may be formed so that thewavelength converting layer 500 is spaced apart from the semiconductorstacked structure, i.e., so that a transparent resin 550 is interposedbetween the wavelength converting layer 500 and the semiconductorstacked structure.

Accordingly, as the wavelength converting layer 500 is spaced apart fromthe semiconductor stacked structure, it is possible to prevent a resinor a phosphor in the wavelength converting layer 500 from beingdeteriorated by light generated in the active layer (not shown). In thiscase, the transparent resin 550 may also be interposed between thewavelength converting layer 500 and an inner surface of the first slit1110 formed in the submount substrate 1000 (region B of FIG. 28).

Here, in order to reduce heat transferred to the phosphor, the electricconductivity of the transparent resin 550 may be relatively low. Forexample, the electric conductivity of the transparent resin may be lessthan 3 W/mK. TiO₂, SiO₂ or Y₂O₃ may be incorporated into the transparentresin so as to control the refractive index of the transparent resin550.

Alternatively, although not shown in this figure, a high-hardnesstransparent resin (not shown) having a higher hardness than thetransparent resin 550 may be additionally formed on top of thewavelength converting layer 500 so as to cover the wavelength convertinglayer 500. In this case, the high-hardness transparent resin can protectthe phosphor from external moisture. In order to prevent moistureabsorption, the high-hardness transparent resin may have, for example, adurometer Shore hardness of 60A or greater. Further, TiO₂, SiO₂ or Y₂O₃may be incorporated into the high-hardness transparent resin so as tocontrol the refractive index of the high-hardness transparent resin.

As described above, the LED chip and the method of fabricating the same,and a package having the LED chip and the method of fabricating the sameaccording to the present invention are not limited to the aforementionedexemplary embodiments, but may applied to various structures of lightemitting devices containing wavelength converting materials.

According to the present invention, it is possible to provide an LEDchip capable of performing wavelength conversion even with respect tolight emitted through side surfaces of a substrate.

Also, it is possible to provide an LED chip in which additionalelectrodes are employed, thereby performing wavelength conversion andeasily performing wire bonding.

Also, a spacer layer is employed, so that it is possible to prevent aphosphor in a wavelength converting layer from being damaged by lightemitted from a semiconductor stacked structure.

Also, the spacer layer includes a DBR, so that it is possible to lightconverted in the wavelength converting layer from being again incidentinto the semiconductor stacked structure, thereby improving lightefficiency.

Although some exemplary embodiments of the present invention aredescribed for illustrative purposes, it will be apparent to thoseskilled in the art that various modifications and changes can be madethereto within the scope of the invention without departing from theessential features of the invention. Accordingly, the aforementionedexemplary embodiments should be construed not to limit the technicalspirit of the present invention but to be provided for illustrativepurposes so that those skilled in the art can fully understand thespirit of the present invention. The scope of the present inventionshould not be limited to the aforementioned exemplary embodiments butdefined by appended claims. The technical spirit within the scopesubstantially identical with the scope of the present invention will beconsidered to fall in the scope of the present invention defined by theappended claims.

What is claimed is:
 1. A light emitting diode (LED) chip, comprising: asubstrate; a GaN-based compound semiconductor stacked structure arrangedon the substrate, the semiconductor stacked structure comprising a firstconductivity-type semiconductor layer, an active layer, and a secondconductivity-type semiconductor layer; an electrode electricallyconnected to the semiconductor stacked structure; and a wavelengthconverting layer covering a portion of the semiconductor stackedstructure, wherein the electrode passes through the wavelengthconverting layer, wherein the electrode comprises a first electrodearranged on the semiconductor stacked structure, and a first additionalelectrode arranged on the first electrode, wherein the entire lowersurface of the first additional electrode is arranged entirely on thefirst electrode, wherein the wavelength converting layer is disposedwith a uniform thickness on side surfaces of the substrate and theGaN-based compound semiconductor stacked structure, and wherein the sidesurfaces of the substrate and the GaN-based compound semiconductorstacked structure are substantially flush.
 2. The LED chip of claim 1,further comprising a spacer layer disposed between the wavelengthconverting layer and the semiconductor stacked structure.
 3. The LEDchip of claim 2, wherein the spacer layer comprises an insulating layer.4. The LED chip of claim 2, wherein the spacer layer comprises adistributed Bragg reflector (DBR).
 5. The LED chip of claim 4, whereinthe spacer layer further comprises a stress relaxation layer disposedbetween the DBR and the semiconductor stacked structure.
 6. The LED chipof claim 5, wherein the stress relaxation layer comprises a spin onglass (SOG) or a porous silicon oxide film.
 7. The LED chip of claim 1,wherein the first additional electrode is narrower than the firstelectrode.
 8. The LED chip of claim 7, wherein the width of the firstadditional electrode decreases in a direction away from the firstelectrode.
 9. The LED chip of claim 1, further comprising a secondelectrode arranged on and electrically connected to the semiconductorstacked structure, and a second additional electrode arranged on thesecond electrode.
 10. The LED chip of claim 1, wherein a top surface ofthe first additional electrode is flush with a top surface of thewavelength converting layer.
 11. The LED chip of claim 10, wherein thetop surface of the additional electrode and the top surface of thewavelength converting layer are substantially flat.
 12. The LED chip ofclaim 10, wherein the top surface of the first additional electrode isopposite to the first electrode, and the first additional electrode topsurface is not covered by the wavelength converting layer.
 13. The LEDchip of claim 1, wherein the electrode is electrically connected to thefirst conductivity-type semiconductor layer.
 14. A light emitting diode(LED) package, comprising: a lead terminal; an LED chip; and a bondingwire connecting the lead terminal and the LED chip, wherein the LED chipcomprises: a substrate; a GaN-based compound semiconductor stackedstructure arranged on the substrate, the semiconductor stacked structurecomprising a first conductivity-type semiconductor layer, an activelayer, and a second conductivity-type semiconductor layer; an electrodeelectrically connected to the semiconductor stacked structure; and awavelength converting layer covering a portion of the semiconductorstacked structure, wherein the electrode passes through the wavelengthconverting layer, and the bonding wire connects the electrode and thelead terminal, wherein the electrode comprises a first electrodearranged on the semiconductor stacked structure, and a first additionalelectrode arranged on the first electrode, wherein the entire lowersurface of the first additional electrode is arranged entirely on thefirst electrode, wherein the wavelength converting layer is disposedwith a uniform thickness on side surfaces of the substrate and theGaN-based compound semiconductor stacked structure, and wherein the sidesurfaces of the substrate and the GaN-based compound semiconductorstacked structure are substantially flush.
 15. The LED package of claim14, further comprising a spacer layer disposed between the wavelengthconverting layer and the semiconductor stacked structure.
 16. The LEDpackage of claim 14, wherein the first additional electrode is narrowerthan the first electrode.
 17. The LED package of claim 16, wherein thewidth of the first additional electrode decreases in a direction awayfrom the first electrode.
 18. The LED package of claim 14, wherein theelectrode is electrically connected to the first conductivity-typesemiconductor layer.